You should be fine but you underpitched some if you didn't. Give it some more time. Sometimes fermentation can take a while to start.

BTW airlock activity is not a fermentation indicator. The only way to tell is with a gravity reading. If you are using a bucket the lids sometimes don't seal properly and you will see no airlock activity.

I agree with beer golf. It's likely that you under pitched....and 1.060 is nowhere near a maximum OG for a Belgian strain. In fact, it doesn't really work that way. Most yeast pretty capable of handling high alcohol levels in your beer and 1.060 isn't a particularly high OG.

I would wait until tomorrow morning at least if you didn't make a starter initially. The yeast will increase their numbers to amounts sufficient to ferment the beer then start the serious fermentation.

It would not surprise me to have a lag time of 36 to 48 hours if you underpitched.

72 hours is often cited as the time to get concerned and consider other measures to start fermentation.

The "potentially" nice thing about Belgian strains is that you are looking for "character" from it. Your yeast just went through a bigger than normal growth phase which is the time that most of your esters and phenols are created. I think your beer will eventually take off. It just might have some extra Belgian character. Hopefully, your wort was clean and the long lag time didn't allow some nasties to take hold. Good luck, in my experience, mistakes still make good beer!

The "potentially" nice thing about Belgian strains is that you are looking for "character" from it. Your yeast just went through a bigger than normal growth phase which is the time that most of your esters and phenols are created. I think your beer will eventually take off. It just might have some extra Belgian character. Hopefully, your wort was clean and the long lag time didn't allow some nasties to take hold. Good luck, in my experience, mistakes still make good beer!

Agree with this post. You'll likely end up with some more ester character, and this is a beer that you expect lots of esters. So long as you didn't have something else in there, you should be fine.